CN102850239B - Method for producing isocyanates - Google Patents

Abstract

The present invention relates to a method for producing isocyanates by reacting the corresponding diamines with a stoichiometric excess of phosgene in at least one reaction zone,the reaction conditions are selected so that at least the reaction components diamine, diisocyanate and phosgene are gaseous under these conditions and at least one diamine-comprising gas stream and at least one phosgene-comprising gas stream are fed into the reaction zone, the mass fraction of bromine in the phosgene comprising stream is less than 50 ppm by weight before mixing with the amine -comprising stream.

Description

Prepare the method for isocyanic ester

The application is the divisional application of the patent application that application number is 200780050093.7, the applying date is on December 12nd, 2007, denomination of invention is " preparing the method for isocyanic ester ".

The present invention relates to a kind of method of being prepared vulcabond in gas phase by diamines photoreactive gas.

EP 570799, embodiment 1 has described the reaction mixture that aftertreatment obtains by gas phase phosgenation by washing tower, and wherein water droplet flows by washing tower to separate phosgene and hydrogenchloride.

This aftertreatment destroys excess phosgene and hydrogen chloride gas no longer can be advantageously used in reaction them.

EP 593334B1 and EP 699657B1 disclose and have utilized or destroyed the possibility of phosgene or hydrogen chloride gas, but do not probe into the particular problem relevant to recirculation phosgene.

[0018] section of [0018] section of EP 749 958B1 and EP 1078918B1 mention the hydrogen chloride gas that reclaims excess phosgene and recovery after triamine gas phase phosgenation and are used further to the possibility of phosgene in synthetic.

Here do not provide the detailed description of recirculation phosgene yet.

US 4,581,174 has described by make primary amine phosgenation continuous production organic single-isocyanate and/or polyisocyanates in mixed circuit, wherein comprises the reaction mixture part recirculation of isocyanic ester, and the HCl ratio in recirculation mixture is for being less than 0.5%.Here isocyanic ester is recycled to the formation of the promotion urea in reaction zone with unhindered amina continuously.The stable operation of the urea harm method of precipitation.

GB 737 442 has described by the synthetic middle phosgene that reclaims of isocyanic ester.The HCl content of the phosgene reclaiming is 0.5-0.7%.

The HCl content that DE 10261191A1 and WO 2004/58689 have described the feed steam that wherein comprises phosgene is to be less than 0.4 or be greater than the phosgenation of 0.8 % by weight.

Those that problem that gas phase phosgenation comprises that these files are as broad as long and liquid phase phosgenation comprise, and preferably only relate to liquid phase phosgenation.

The shortcoming of all these methods is cl contenies of having ignored during phosgene or phosgenation.

Application number is PCT/EP2006/064850 and the applying date to be that the international patent application on July 31st, 2006 has been described process for gas phase phosgenation, and wherein hydrogen chloride content should remain on below specific threshold.

WO 04/56758 mentions the chlorine as phosgene component in wide secondary component row, but does not instruct any particular problem about chlorine content in gas phase phosgenation.

US 3331873 discloses a kind of chlorine that separates from phosgene by activated carbon to the usual method that is less than 25ppm content.

In disclosed method, do not relate in phosgenation, particularly the particular problem in gas phase phosgenation.

WO 01/00569 has described bromine and the effect of bromine-containing compound content to colour in liquid phase phosgenation at the pressure of 100 bar at the most and 0-130 DEG C.

In disclosed method, do not relate to the particular problem in gas phase phosgenation.

Gas phase phosgenation carries out conventionally at 200-600 DEG C.Due to these high temperature, the design of method must meet particular requirement can be due to material with the prolonged operation of implementation method, the stress particularly improving in high temperature range on reactor wall and revealing.

High temperature is combined with corrodibility reaction medium and is produced the specific demand to method and material therefor.For example, known high temperature (approximately 400 DEG C or more than) under, phosgene autocatalysis is separated into molecule chlorine (Cl ₂) and carbon monoxide (CO).At high temperature, chlorine can cause raw material embrittlement by mixing material.If for example inevitable earthquake motion in preparation facilities, the material of embrittlement, particularly reactor wall can be subject to stress and fracture or break like this, make to reveal possibility raising.In addition, chlorine can be with non-steel alloy at 170 DEG C with up and down with chloro-iron burning thermopositive reaction.This is especially industrial problem processing very in toxicity phosgene.

Therefore, the object of this invention is to provide one makes diamines in gas phase, react to form the method that corresponding vulcabond and hydrogenchloride (HCl) carry out can reduce the mode of material fragility with phosgene.

This object realizes by the method for preparing vulcabond by a kind of, wherein makes corresponding diamines react at least one reaction zone with stoichiometry excess phosgene,

Wherein to make at least reactive component diamines, vulcabond photoreactive gas be gaseous state under these conditions in the selection of reaction conditions, and

The air-flow that at least one is comprised to diamines and the air-flow that at least one comprises phosgene feed in reaction zone,

In the material stream that wherein comprised phosgene before mixing with the material stream that comprises amine, the massfraction of chlorine is that the massfraction of bromine during the material that is less than 1000 ppm by weight and/or comprises phosgene flows is for being less than 50 ppm by weight.

According to the present invention; in gas phase phosgenation; should endeavour to ensure the compound existing between the reaction period, any inert compound of starting raw material (diamines photoreactive gas), intermediate (the mono amino formyl radical and the dimethylcarbamyl chloride that particularly form as intermediate), final product (vulcabond) and introducing keeps gas phase under reaction conditions.If these or other component by being for example deposited in gas phase on other assemblies of reactor wall or equipment, conduct heat or flow through affected assembly can by these settlings undesirable change.This is specially adapted to the amine hydrochloride being formed by free amine group and hydrogenchloride (HCl), and this is because gained amine hydrochloride is easy to precipitation and is difficult to again gasify.

In preferred embodiments, except reducing according to the present invention chlorine content, can make after any and fresh phosgene mix and mixes with the material stream that comprises amine before the hydrogenchloride massfraction flowing containing phosgene material for being less than 15 % by weight, be preferably less than 10 % by weight, be particularly preferably less than 5 % by weight.

Such result is that the formation of amine hydrochloride can significantly reduce, and makes the Risk Reduction that in reactor, settling forms.

Due to feed reaction according to low chlorine content (mol-chloric (Cl thus of the present invention ₂)), diamines can be changed into overall chlorine content during corresponding vulcabond and keep low as far as possible and no matter separates by phosgene the chlorine forming between the reaction period, the risk of material embrittlement and/or the burning of chloro-iron can be reduced or even elimination.

According to the present invention, after any and fresh phosgene mix and before mixing with the material stream that comprises amine, the chlorine content of the material stream that comprises phosgene is for being less than 1000 ppm by weight, preferably be less than 500 ppm by weight, particularly preferably be less than 250 ppm by weight, very particularly preferably be less than 100 ppm by weight, be particularly less than 50 ppm by weight, be especially less than 25 ppm by weight.

Substituting in addition or as it, after any and fresh phosgene mix and before mixing with the material stream that comprises amine, in the material stream that comprises phosgene with the bromine or iodine of molecule or combining form or the content of its mixture for being less than 50 ppm by weight, preferably be less than 40 ppm by weight, 35 ppm by weight, 30 ppm by weight, 25 ppm by weight or still less, particularly 10 ppm by weight or still less, especially 5 ppm by weight, 3 ppm by weight, 2 ppm by weight or 1 ppm by weight or still less.

With regard to herein, the bromine or iodine of molecular form is for only by the former molecular molecule of bromine or iodine.The bromine or iodine of statement combining form refers to not only comprise bromine or iodine, also comprises other atoms that are different from described atom in every kind of situation.Except as otherwise noted, in this article, term " bromine " refers to molecular bromine (Br ₂).

In the methods of the invention, phosgene carries out with reacting in gas phase of diamines.

The vulcabond that can prepare by the inventive method can be aromatics, alicyclic or aliphatic vulcabond.

Alicyclic isocyanate is to comprise those of at least one alicyclic member ring systems.

Aliphatic isocyanate is only to have those of the isocyanate groups that is bonded on straight or branched.

Aromatic isocyanate is to have at least one to be bonded in those of isocyanate groups at least one aromatic ring system.

With regard to present patent application, statement (ring) aliphatic isocyanate writing a Chinese character in simplified form as alicyclic and/or aliphatic isocyanate.

The example of aromatic diisocyanate preferably has those of 6-20 carbon atom, for example single methylene radical two (phenyl isocyanate) (MDI), toluene 2,4-and/or 2,6-vulcabond (TDI) and naphthyl vulcabond (NDI).

Vulcabond is (ring) aliphatic vulcabond preferably, particularly preferably has (ring) aliphatic vulcabond of 4-20 carbon atom.

The example of conventional vulcabond is that aliphatic vulcabond is as tetramethylene diisocyanate, pentamethylene diisocyanate (1, 5-bis-isocyanato-pentanes), 2-methyl isophthalic acid, 5-bis-isocyanato-pentanes, hexamethylene diisocyanate (1, 6-bis-isocyanato-hexanes), eight methylene radical 1, 8-vulcabond, decamethylene 1, 10-vulcabond, ten dimethylenes 1, 12-vulcabond, ten tetramethylenes 1, 14-vulcabond, lysinediisocyanate derivative, tetramethylxylene diisocyanate (TMXDI), trimethyl cyclohexane vulcabond or tetramethyl-hexane diisocyanate and 3 (or 4), 8 (or 9)-bis-(isocyanato-methyl), three ring [5.2.1.0 ^2.6] decane isomer mixture and alicyclic diisocyanate, for example Isosorbide-5-Nitrae-, 1,3-or 1,2-bis-isocyanato-hexanaphthenes, 4,4 '-or 2,4 '-bis-(isocyanato-cyclohexyl) methane, 1-isocyanato--3,3,5-trimethylammonium-5-(isocyanato-methyl) hexanaphthene (isophorone diisocyanate), 1,3-or Isosorbide-5-Nitrae-bis-(isocyanato-methyl) hexanaphthene, 2,4-or 2,6-, bis-isocyanato-s-1-methylcyclohexane.

Preferably 1,6-bis-isocyanato-hexanes, 1-isocyanato--3,3,5-trimethylammonium-5-(isocyanato-methyl) hexanaphthene, 4,4 '-bis-(isocyanato-cyclohexyl) methane and toluene diisocyanate isomers mixtures.Particularly preferably 1,6-bis-isocyanato-hexanes, 1-isocyanato--3,3,5-trimethylammonium-5-(isocyanato-methyl) hexanaphthene and 4,4 '-bis-(isocyanato-cyclohexyl) methane.

In the methods of the invention, can preferably become gas phase and significantly decompose amine can be used for reaction to form corresponding vulcabond.Here particularly suitable amine is based on having the aliphatic series of 2-18 carbon atom or the amine of clicyclic hydrocarbon, particularly diamines.Example is 1，6-diaminohexane, 1-amino-3,3,5-trimethylammonium-5-amino methyl hexanaphthene (IPDA) and 4,4 '-diamino-dicyclohexyl methane.Preferably use 1，6-diaminohexane (HDA).

Can will be able to preferably become gas phase equally and Undec aromatic amine for the inventive method.The example of preferred aromatic amine is as 2,4 or 2, the toluylene diamine (TDA) of 6 isomer or its mixture, diaminobenzene, naphthylene diamine (NDA) and 2,4 '-or 4,4 '-methylene radical two (phenyl amine) (MDA) or its isomer mixture.Among these, preferably diamines, particularly preferably 2,4-and/or 2,6-TDA.

Starting raw material or the only one in them can be introduced reaction compartment together with inert media.

Other inert medias can be introduced in the inventive method.Inert media is to be present in reaction compartment and the medium during reaction not reacting with the compound existing with gaseous state under temperature of reaction.Conventionally inert media was mixed with amine and/or phosgene before reaction, but also can open infeed with starting raw material material flow point.For example can use nitrogen, rare gas if helium or argon gas or aromatic hydrocarbon are as chlorobenzene, dichlorobenzene, dimethylbenzene, carbonic acid gas or carbon monoxide.Preferably use nitrogen and/or chlorobenzene as inert media.

Conventionally inert media uses taking such amount conventionally: inert media compares as >0.0001 to 30 with amine or with the gas volume of phosgene, preferably >0.01 to 15, particularly preferably >0.1 to 5.

Preferably inert media is introduced in reaction compartment together with diamines.

By the material stream that comprises phosgene, phosgene being introduced to reaction compartment also can be by the material stream that replaces sub-thread comprise phosgene, feeds the subflow that multiply comprises phosgene and carries out.In this case, the subflow that comprises phosgene adds up to the total material stream that comprises phosgene, and in the total material stream that comprises phosgene, the massfraction of chlorine keeps the massfraction of chlorine in molecule each subflow that comprises phosgene under not reacting to obtain by supposing.The massfraction value of the chlorine calculating so in this case, is for notional total phosgene material stream.

Analogue is applicable to bromine content.

This seed flow can be introduced as follows:

-can be by various containing phosgene subflows before introducing and infeed reaction compartment, for example recirculation phosgene and fresh phosgene are combined to form containing phosgene always expects stream.

-multiply subflow (in its every kind situation, can be recirculation phosgene, fresh phosgene or its mixture) can be fed to reaction compartment as follows in same position, for example, via the multiple nozzles that are arranged in parallel around central nozzle, for example, as described in EP 1449826A1, introduce by circular clearance, for example, if application number is PCT/EP2006/065593 and the applying date to be as described in the international patent application on August 23rd, 2006, or by this material stream with introduce by central nozzle mix containing amine material stream before repeatedly inject annular space with mixing.

-multiply subflow (can be recirculation phosgene, fresh phosgene or its mixture in its every kind situation) can be made during reaction to introduce other phosgene at the various positions introducing in reaction compartment.

Therefore, term " fresh phosgene " refers to not by recirculation in phosgenation process and not flowing by the phosgene material that contains of the step of reaction including phosgene reaction, wherein, in phosgene reaction, the phosgene that is greater than 5% preparation in phosgene is synthetic reacts after conventionally by chlorine and the synthetic phosgene of carbon monoxide.

If by one or more strands of extra flowing and feed reaction compartment without gaseous phosgene or without the inertia material of amine,, in the time carrying out the inventive method, in the calculating of always expecting containing phosgene to flow, these are considered to always expect containing phosgene the subflow flowing.

For carrying out the inventive method, before mixing, conventionally can advantageously the material stream of reactant be preheated to 100-600 DEG C, preferably 200-450 DEG C.

In amine storage vessel, preferably make amine become gas phase and feed mixing device together with nitrogen with the inert media as carrier gas.But, also can not use inert media and amine is directly evaporated.If make equally phosgene suitable together with inert media by becoming gas phase in phosgene storage vessel and introducing mixing device.

In the methods of the invention, reactant is mixed in mixing device, wherein make to stand high-shear by the reacting material flow of mixing device.As mixing device, be preferably contained in static mixing device or the mixing nozzle of reactor upstream.Particularly preferably use mixing nozzle.

According to the present invention, the kind of mixing is unessential, and mixing can be with for example EP-B1699657, EP-A2 1319655, the 1st hurdle the 54th walks to the 2nd hurdle the 24th row, capable with the 4th hurdle 16-40, EP-A1 1275640, the 3rd hurdle the 27th walks to the 4th hurdle the 5th row, EP-A2 1362847, the 2nd hurdle the 19th walks to the 3rd hurdle the 51st row and the 4th hurdle the 40th walks to the 5th hurdle the 12nd row, or application number is PCT/EP2006/065593 and the applying date to be the international patent applications on August 23rd, 2006, any mode that page 2 the 23rd walks to described in page 1 the 22nd row is carried out, in every kind of situation, its full content is introduced to the disclosure of invention as a reference.

According to the present invention, phosgene is with than the excessive use of amino.Phosgene and amino mol ratio are generally 1.1:1-20:1, preferably 1.2:1-5:1.

After mixing in mixing device, if the gaseous mixture of phosgene, amine and suitable inert media is fed in the reactor that comprises reaction compartment.

Phosgene carries out with reacting in reaction compartment of amine, reaction compartment is usually located in reactor, be that reaction compartment is to be arranged in the starting raw material of reactor and the major part of intermediate is reacted the space of carrying out, for example at least 0.5 % by mole, preferably at least 1 % by mole, particularly preferably at least 3 % by mole, very particularly preferably at least 5 % by mole, particularly at least 7 % by mole, especially at least 10 % by mole of amine used change into corresponding isocyanic ester.

For the present invention, reactor is the industrial equipments that comprises reaction compartment.Reaction compartment can be for known by prior art and be suitable for on-catalytic single phase gas and react, the preferably popular response space of on-catalytic single phase gas reaction continuously, and will stand required moderate pressure.Be suitable for the material of reaction mixture contact for example for metal is as steel, particularly steel alloy, tantalum, nickel, nickelalloy, silver or copper, glass, pottery, enamel or the homogeneous that comprises these or heterogeneous mixture and the assembly that comprises them.Preferably use steel equipment, particularly preferably steel reactor.The wall of reactor can be smooth or have structure.What be applicable to is configured to groove or ripple.

Conventionally can use the known structure of reactor of prior art.The example of reactor is by EP-B1289840, the 3rd hurdle the 49th Hang – the 4th hurdle the 25th row, EP-B1 593334, WO 2004/026813, the 6th page of the 10th row of page 3 the 24th Hang –, WO 03/045900, the 6th page of the 15th row of page 3 the 34th Hang –, EP-A1 1275639, the 4 hurdle the 17th Hang – the 5th hurdle the 17th row and EP-B1570799, the 2nd hurdle the 1st Hang – the 3rd hurdle the 42nd row is known, in every kind of situation, its full content is introduced to the disclosure of invention as a reference.

Preferably use tubular reactor.

Can use equally cube reaction compartment substantially, preferably plate-type reactor or board-like reaction compartment.The ratio of the wide and height of particularly preferred plate-type reactor is 2:1 at least, preferably 3:1 at least, particularly preferably 5:1 at least, particularly 10:1 at least.The upper limit of the ratio of wide and height depends on required reaction compartment ability and does not limit in principle.The ratio of having found wide and height is 5000:1 at the most, and preferably the peaked reaction compartment of 1000:1 is that industry is useful.

In reaction compartment, phosgene clings to the bar to <20 with reacting at >0.1 of amine, and preferably 0.5-15 bar, particularly preferably carries out under the absolute pressure of 0.7-10 bar.In the case of the reaction of (ring) aliphatic amine, absolute pressure is 0.7-5 bar very particularly preferably, particularly 0.8-3 bar, especially 1-2 bar.

Conventionally lead to pressure in the feed-pipe of mixing equipment higher than above-mentioned pressure in reactor.This pressure is depended in the selection of mixing equipment.Pressure in feed-pipe is preferably than high 20-2000 millibar in reaction compartment, particularly preferably high 30-1000 millibar.

In preferred embodiments, reactor comprises a bundle reactor.In a possible embodiment, mixing device is not necessary for device separately; But, can advantageously mixing device be combined in reactor.The example of the machinery being made up of mixing device and reactor is the tubular reactor with flanged nozzle.

Conventionally, the pressure in finishing apparatus is lower than reaction compartment.Pressure is preferably than the low 50-500 millibar of reaction compartment, particularly preferably 80-150 millibar.

In the methods of the invention, phosgene carries out with reacting in gas phase of amine.For the present invention, reaction in gas phase means feed steam and intermediate reacts to each other to form product with gaseous state and warp keeps gas phase at least 95% in the reaction process by during reaction compartment, preferably at least 98%, particularly preferably at least 99%, very particularly preferably at least 99.5%, particularly at least 99.8%, especially at least 99.9% degree.

Intermediate is for example mono amino mono amino formyl chloride, dimethylcarbamyl chloride, mono amino monoisocyanates and the single isocyanato-mono amino formyl chloride being formed by diamines and the hydrochloride of aminocompound.

In the methods of the invention, more than the selection of the temperature in reaction compartment makes boiling point that it is diamines used based on partial pressure conditions prevailing in reaction compartment.Depend on the pressure of amine used and setting, in reaction compartment, favourable temperature is generally more than 200 DEG C, preferably more than 260 DEG C, particularly preferably more than 300 DEG C.Temperature is generally 600 DEG C at the most, preferably at the most 550 DEG C.

The average contact time of reaction mixture is generally 0.001 second to <5 second in the methods of the invention, preferably >0.01 second to <3 second, particularly preferably >0.015 second to <2 second.In the situation that (ring) aliphatic amine reacts, average contact time can be very particularly preferably 0.015-1.5 second, particularly 0.015-0.5 second, especially 0.020-0.1 second, is generally 0.025-0.05 second.

In preferred embodiments, mobile in the inventive method has and is greater than 10, is preferably greater than 100, is particularly preferably greater than 500 Bodenstein value.

In preferred embodiments, the selection of reaction compartment size and velocity of flow makes to exist turbulent flow, and NR is at least 2300, particularly preferably flowing of 2700 reaction mixture, and wherein NR uses the hydraulic diameter of reaction compartment to form.

Gaseous reaction mixture is preferably with 10-300 meter per second, preferably 25-250 meter per second, particularly preferably 40-230 meter per second, very particularly preferably 50-200 meter per second, particularly >150 to 190 meter per second, especially the velocity of flow of 160-180 meter per second is passed through reaction compartment.Due to turbulent flow, the narrow residence time and the well blend conventionally with the little standard deviation that is not more than 6% are realized as described in EP570799.Do not need measure to compress as described in EP-A-593 334, this compression also easily causes obstruction.

Reaction volume can be via its outside surface heating/cooling.For building the production equipment with high plant capacity, multiple reaction tubess can be connected in parallel.But reaction also can preferably be carried out adiabaticly.This does not mean not because the heating of engineering measure or cooling energy are by the outside surface of reaction volume.React preferred carries out adiabaticly.

The inventive method is preferably carried out in the single stage.For the present invention, this means the mixing of starting raw material and reacts in a step and a temperature range, preferably within the scope of said temperature, carries out.In addition, the inventive method is preferably carried out continuously.

After reaction, preferably gaseous reaction mixture is used at the temperature higher than 130 DEG C to solvent wash (quenching).Preferred solvent is that the hydrocarbon that can optionally be replaced by halogen atom is as chlorobenzene, dichlorobenzene and toluene.Particularly preferably use monochloro benzene as solvent.Also can use isocyanic ester as solvent.Be in the suds, be transferred in washing soln selective isocyanate.Subsequently residual gas and the washing soln obtaining are preferably divided into isocyanic ester, solvent, phosgene and hydrogenchloride by rectifying.Preferably use isocyanic ester.

In reaction compartment, after reaction, it is moved in the finishing apparatus with quenching at reaction mixture.This preferred washing tower is wherein isolated by condensation in inert solvent the isocyanic ester of formation from gaseous mixture, and if excess phosgene, hydrogenchloride and suitable inert media pass through finishing apparatus with gaseous form.Preferred inert solvent is that the hydrocarbon that can optionally be replaced by halogen atom is as chlorobenzene, dichlorobenzene and toluene.More than the temperature of inert solvent preferably remains on the solvent temperature of the urea chloride that is derived from amine in selected quenching medium.More than the temperature of inert solvent particularly preferably remains on the fusing point of the urea chloride that is derived from amine.

Washing can for example at stirred vessel or at other conventional equipments, for example, be carried out in tower or mixer-settler equipment.

Aspect process engineering, all known extractions own and washing methods and equipment can be used for the washing in the inventive method, for example be described in Ullmann ' s Encyclopedia of Industrial Chemistry, the 6th edition, 1999 electronic editions, chapters and sections: those in Liquid – Liquid Extraction – Apparatus (liquid-liquid extraction-device).These can be for example single-stage or multistage, preferably single-stage extraction and also stream or adverse current, those of preferred counter-current operation.

Applicable quenching can be for example by EP-A1 1403248, application number be 06123629.5 and the applying date be the 2nd hurdle the 39th hurdle, row-3rd the 18th row of european patent application on November 7th, 2006 or application number be 06123621.2 and the applying date be known in the european patent application on November 7th, 2006, be introduced in the disclosure of invention as a reference.

In this quench region, substantially by isocyanic ester, phosgene and hydrogenchloride and chlorine and/or the bromine reaction mixture forming and the liquid intense mixing spraying into.Mix the temperature that makes reaction mixture and reduce 50-300 DEG C by originally 200-500 DEG C, preferably 100-250 DEG C, and the isocyanic ester being included in reaction mixture enters the drop spraying into wholly or in part due to condensation, and phosgene and hydrogenchloride and chlorine and/or bromine are retained in gas phase substantially completely.

Isocyanate content in the gas reaction mixture isocyanic ester based on being included in reaction mixture that is included in that enters liquid phase in quench region is preferably 20-100 % by weight, particularly preferably 50-99.5 % by weight, particularly 70-99 % by weight.

Reaction mixture is preferably downward through quench region from top.Below quench region, there is collection container, wherein take out and aftertreatment subsequently from reaction compartment by liquid-phase precipitation, collection and via outlet.Remaining gas phase is taken out from reaction compartment via second outlet and same aftertreatment.

Quenching can for example be carried out as described in EP 1403248A1 or as described in WO 2005/123665.

Drop for this object passes through list or dual-flow atomizer nozzle, and preferably single fluid atomizer nozzle produces, and depends on that design produces 10-140 °, preferred 10-120 °, the particularly preferably spray cone angle of 10 °-100 °.

The liquid spraying into via atomizer nozzle must have the good solvent ability to isocyanic ester.Preferably with an organic solvent.The aromatic solvent that special use can be replaced by halogen atom.The example of this liquid is toluene, benzene, oil of mirbane, phenylmethylether, chlorobenzene, dichlorobenzene (adjacent, to), trichlorobenzene, dimethylbenzene, hexane, dimethyl isophthalate (DEIP), tetrahydrofuran (THF) (THF), dimethyl formamide (DMF) and composition thereof, preferably monochloro benzene.

In the special embodiment of the inventive method, mixture or the isocyanic ester of mixture, isocyanic ester and solvent that the liquid spraying into is isocyanic ester, wherein in every kind of situation, quench liquid used can comprise part low boilers as HCl photoreactive gas.Preferably use the isocyanic ester of preparing in each method.Because reaction in quench region is reduced and stopped by temperature, can get rid of and the secondary reaction that sprays into isocyanic ester.The advantage of this scheme particularly does not need to isolate solvent.

In selectable preferred embodiment, the inert media using together with at least one starting raw material and the solvent for quenching are same compound; In this case, very particularly preferably use monochloro benzene.

The by product being retained on a small quantity in isocyanic ester can, by extra rectifying, with rare gas element stripping or crystallization, preferably be removed from required isocyanic ester by rectifying.

In optional purification step subsequently, by isocyanic ester preferably by rectifying and separated from solvent.Residual impurity particularly including chlorine and/or bromine and hydrogenchloride, inert media and/or phosgene can equally here separate, for example, as described in DE-A1 10260092.

Substantially formed by phosgene and/or hydrogen chloride gas, but the material stream that also comprises part chlorine is obtained by quenching and/or purification phase.According to the present invention, by chlorine and/bromine isolates from comprising phosgene and/or hydrogen chloride gas and chlorine and/or bromine and being recycled in the phosgene at least part of these material stream of reaction, before making to mix after any and fresh phosgene mix with the material stream that comprises amine, the massfraction of the chlorine in the material stream that comprises phosgene is for being less than 1000 ppm by weight, and/or the massfraction of bromine is for being less than 50 ppm by weight, this as described herein.

In feasible embodiment, the chlorine content of the air-flow that comprises phosgene is at least 0.05 ppm by weight or at least 0.1 ppm by weight even, even if not, and at least 1 ppm by weight.Also can be at least 5 ppm by weight.

In feasible embodiment, the bromine content of the air-flow that comprises phosgene is at least 0.005 ppm by weight or at least 0.01 ppm by weight even, even if not, and at least 0.1 ppm by weight.Also can be at least 0.5 ppm by weight.

The separation of the mixture that comprises hydrogenchloride and/or phosgene and/or solvent and/or chlorine and/or bromine is preferably undertaken by partial condensation and/or rectifying and/or washing.Separate and preferably carry out with the rectifying of any order and the combination of washing.

Washing

Preferred washing medium is the above-mentioned solvent as quenching medium.The particularly preferably use solvent identical with washing medium and quenching medium.

In the washing and rectifying of combination, phosgene passes through with washing medium, preferably toluene, chlorobenzene or dichlorobenzene, and particularly preferably chlorobenzene washs and washs out in being flowed by the material containing HCl.This produces load the washing medium of phosgene and hydrogenchloride and common chlorine.Phosgene, hydrogenchloride (HCl) and mol-chloric (Cl ₂) from wash this later load washing medium, separate and preferably undertaken by distillation.

Washing, in 1-10 bar absolute pressure, is preferably carried out under 1-5 bar absolute pressure.

Washing is preferably at-5 to-40 DEG C, and preferably-15 to-35 DEG C, operation at particularly preferably-20 to 30 DEG C.

Aspect process engineering, known all absorption process and equipment own can be used for this washing in the present invention, for example be described in Ullmann ' s Encyclopedia of Industrial Chemistry, the 6th edition, 2000 electronic editions, chapters and sections " Absorption (absorption) " and preferred sub-chapters and sections " Design of Absorption Systems (design of absorption system) ", those in " Design of Absorption Equipment (design of absorption unit) " and " Design of Desorption Equipment (design of desorption apparatus) ".These can be for example single-stage or multistage, preferably multistage absorption and also stream or adverse current, those of preferred counter-current operation.

Preferably use the tower that there is tower and the pulse-column of valve tray, sieve tray, structured packing or random packing or there are rotation internals.Preferably washings is passed through to nozzle dispersion in small, broken bits and contacts with gas phase.

According to the present invention, if separate to obtain suitable after mixing with fresh phosgene chlorine content be to be less than 1000 ppm by weight and/or bromine content is the phosgene material stream that is less than 50 ppm by weight.

For the present invention, mixture to be separated is set as 5:1-0.5:1 with the ratio of washings, preferably 3:1-1:1, particularly preferably 2.5:1-1.5:1.

As another embodiment, can use ionic liquid as washings, for example, as WO2006/029788, particularly wherein page 2 the 39th walks to described in the 11st page of the 25th row.

Partial condensation

As selecting or in addition, can be by chlorine and/or bromine by using WO 2004/56758, preferably wherein walk to method partial condensation described in the 13rd page of the 16th row and embodiment for the 11st page the 14th and isolate from the material stream that comprises phosgene and hydrogenchloride.This is incorporated herein by reference the disclosure content again.

This will be preferably by comprising hydrogenchloride photoreactive gas and chlorine and/or bromine, the following fractionation of the mixture of solvent, low boilers and inert substance and realizing if possible: first by comprise phosgene and hydrogenchloride and if possible the material of solvent flow to few part or all, preferred a part of condensation, then in tower, rectifying or stripping, to remove de-chlorine hydride and chlorine and/or bromine from bottoms phosgene, preferably wash top product hydrogenchloride to absorb phosgene in process solvent by process solvent subsequently.For remove solvent residues thing and/or chlorine and/or bromine and/or hydrogenchloride from phosgene, can carry out subsequently by for example on gac absorption or by purifying after other applicable methods.

If suitable, partial condensation can be carried out in multiple stages with under all temps and stress level; In tower, further rectifying or stripping can carry out subsequently to remove de-chlorine hydride and/or chlorine and/or bromine from condensation phosgene.

By phosgene from gained comprise hydrogenchloride, phosgene, chlorine and/or bromine and if possible the mixture of solvent and inert substance part be condensate in one or preferred multiple stage, and depend on the pressure in step of reaction, at-40 DEG C that can realize by refrigerant, to the temperature of 40 DEG C realizing by water coolant, carry out.

Rectifying

If for the rectifying of removing chlorine and/or bromine and suitable hydrogenchloride from the condensation phosgene obtaining like this in bottom at 5-150 DEG C, preferably 5-50 DEG C, cling at 1-35 at top, preferably the pressure of 1.5-4.0 bar and in top-20 DEG C to 30 DEG C, preferably carry out at-10 DEG C to 0 DEG C.

Rectifying can for example have 3-30, preferably in the industrial distillation tower of 5-25 theoretical tray, carries out.

As selection, if also can be by chlorine and/or bromine and suitable hydrogenchloride by removing from recirculation phosgene as nitrogen, process solvent steam, phosgene or other gaseous substances or material stripping to be evaporated with rare gas element.

On gac, adsorb

The phosgene material stream obtaining from phosgene production equipment or after by the mixture distillation that comprises phosgene and hydrogenchloride can have and makes it meet the low chlorine content of standard of the present invention, but it also can need further aftertreatment.

This aftertreatment can preferably be undertaken by the phosgene that absorption comprises chlorine and/or bromine on gac, for example, as described in US 3331873.

The adsorbable quite a large amount of chlorine of gac and/or bromine, for example 20 % by weight at the most, preferably 16 % by weight at the most, and can be by being heated to more than 70 DEG C, preferably 150-250 DEG C and regenerate.

The gac that can be used for present method can be any commercially available gac.Binding mode depends in part on its large area and its mass ratio.Gac can obtain with the independent particle of each degree of porosity.Be suitable for present method from the gac of mineral with by the animal or plant gac obtaining of originating.Find to there is relatively little pore radius, for example approximately preferably

particularly preferably approximately

gac be especially effectively and therefore preferred.

Gac can be used as any formed body, for example, exist as rod, powder, pellet, particle, briquetting or extrudate.

Preferably be generally used for by packing tower or the filled column of gac separated portion from mixture.Also can use other equipment as thering is filtering layer and the container of the agitator of high-power and fast turn-around being housed.The equipment of being convenient to heating or cooling gac is preferably provided.Method itself can be carried out in batches or preferably continuously.

In the example of present method embodiment, the phosgene material that comprises chlorine and/or comprise bromine stream is by absorption tower, the interchanger that this absorption tower is equipped with gac and is had refrigerated brine continuous circulation to pass through around.Thick phosgene enters and is cooled to lower than 8 DEG C in the lower end of tower, and preferably 0 DEG C to-10 DEG C and maintain in the tower at this temperature, and flow through gac.The phosgene of purifying is in tower upper end or leave in its vicinity tower.

The gac exhausting can be by being heated at least 70 DEG C, preferably 150-250 DEG C and regenerate.

For regenerating, can make the gas for inertia under regeneration condition, as the material of nitrogen, argon gas, carbonic acid gas or preferred carbon monoxide flows with 120 – 370kg/m per hour ²the flow velocity of active-carbon bed cross-sectional area flows through gac until it does not basically contain phosgene, comprises and is less than 0.05 volume % phosgene.

According to the present invention, phosgene, from the solvent of quenching, i.e. preferred monochloro benzene, the preferably following preferably combination, particularly partial condensation with processing step that separate of hydrogenchloride and chlorine combines and carries out with rectifying with washing combination or partial condensation.

Mixture to be separated has following composition conventionally:

-from the solvent of quenching: 2-60 % by weight, preferably 5-40 % by weight, particularly preferably 10-30 % by weight,

-phosgene: 20-95 % by weight, preferably 40-85 % by weight, particularly preferably 60-75 % by weight,

-hydrogenchloride: 1-50 % by weight, preferably 2-30 % by weight, particularly preferably 5-20 % by weight, very particularly preferably 5-15 % by weight,

-chlorine: 10-10000 ppm by weight, preferably 10-5000 ppm by weight, particularly preferably 250-3000 ppm by weight, very particularly preferably 500-2000 ppm by weight,

-bromine: 0.01-100 ppm by weight, preferably 0.05-50 ppm by weight, particularly preferably 0.1-10 ppm by weight, very particularly preferably 0.2-10 ppm by weight, and

-vulcabond, its intermediate and product subsequently (total): 0-10 % by weight, preferably 0-5 % by weight, particularly preferably 10 ppm by weight-3 % by weight, very particularly preferably 100 ppm by weight-1 % by weight, condition is and is 100 % by weight.

Fig. 1 is the schematic diagram of first preferred embodiment of the present invention.

In first preferred embodiment, as shown in Figure 1, by this mixture a to be separated _istep a) in introducing portion condensation, mainly comprised solvent, the condensation product a of the phosgene of reducing amount and trace hydrogenchloride and chlorine _h, with the main air-flow a being formed together with trace solvent by phosgene, hydrogenchloride and chlorine _l.This partial condensation is conventionally in 0.1-20 bar absolute pressure, and preferably 0.2-10 clings to absolute pressure, and particularly preferably 0.5-5 bar absolute pressure, very particularly preferably carries out under 0.8-2 bar absolute pressure.The temperature of leaving the material stream of condensation is for example-5 to-40 DEG C, preferably-15 to-35 DEG C, and particularly preferably-20 to-30 DEG C.

Then by the air-flow a obtaining like this _lfeed washing b), washings b described above for wherein this material being flowed _i, preferably counter-current treatment.Washings is preferably identical with the solvent in mixture to be separated.Wash and b) obtain the air-flow b that phosgene and solvent are substantially completely therefrom removed and be substantially made up of hydrogenchloride, chlorine and/or bromine _g.For example, owing to carrying secretly, also can comprise washings.Material stream b _gliquid ingredient can remove by downstream fractionator or drop settling vessel.If suitable, then could be by material stream b _g(suitable words are after other purification step) are delivered to the technique of utilizing hydrogenchloride, for example, as described in DE 10235476 (corresponding to US 6916953).

The utilization of this hydrogenchloride can be preferably preparation of chlorine, preferably electrolysis or very particularly preferably Deacon process.

Liquid b b) being exported by washing step _ltherefore mainly formed by washings, wherein exist most of from introducing stage b) in material stream a _lphosgene.In addition, a small amount of hydrogenchloride and trace chlorine also can be present in washings.

The preferred disposition of washing makes it have 2-25 heating power term, particularly preferably 5-20 heating power term, very particularly preferably 10-15 heating power term.

Washing is conventionally in 0.1-20 bar absolute pressure, and preferably 0.2-10 clings to absolute pressure, and particularly preferably 0.5-5 bar absolute pressure, very particularly preferably operates under 0.8-2 bar absolute pressure.The temperature of washing medium is for example-5 to 40 DEG C, preferably-15 to-35 DEG C, and particularly preferably-20 to-30 DEG C.

The ratio of reaction mixture and washings is as being 5:1-0.5:1, preferably 3:1-1:1, particularly preferably 2.5:1-1.5:1.

Then will expect stream b _land a _hin conjunction with and feed in rectifying c), wherein substantially low boilers chlorine and hydrogenchloride are isolated from phosgene and washings.In preferred embodiments, rectifying c) only comprises stripping stage, is about to feed rectifying material stream c) and feeds rectifying more than isolating active internals.Stripping stage comprises 5-30 theoretical tray conventionally, preferably 10-25 theoretical tray, particularly preferably 15-20 theoretical tray.In the preferred embodiment of religion, rectifying c) can additionally comprise the enrichment section with 2-10 theoretical tray.Rectifying c) conventionally at top at 0-25 DEG C, preferably 5-20 DEG C, the particularly preferably temperature of 10-15 DEG C, in bottom at 20-80 DEG C, preferably 30-70 DEG C, the particularly preferably temperature of 40-60 DEG C, and 1-5 bar absolute pressure, preferably operates under 2-3.5 bar absolute pressure.

Rectifying can be for example with 1-20, preferably 3-15, and particularly preferably the reflux ratio of 5-12 is carried out.

High boiler material stream c _hsubstantially formed by phosgene and washings.Vapor stream c _lhydrogenchloride and chlorine be can not only comprise, and a small amount of phosgene and washings comprised.

In preferred embodiments, by vapor stream c _lthe stage d) in partial condensation make condensation product d _hbe recycled to the stage c).Mainly comprise the air-flow d of hydrogenchloride and chlorine and a small amount of phosgene _lthe introducing stage a).

If treat that the fresh phosgene in the whole technique of the infeed separating has high chlorine content in the inventive method, for example, more than 2 ppm by weight, preferably more than 10 ppm by weight, particularly preferably more than 20 ppm by weight, very particularly preferably more than 50 ppm by weight, particularly more than 100 ppm by weight, according to the present invention, this fresh phosgene that comprises chlorine is at least part of before processing with amine, preferably all by the isolating active internals of rectifying tower.This can be for example feeds the stage c) by the fresh phosgene that preferably this is comprised to chlorine, particularly preferably in flowing and feed the stage on identical theoretical tray and c) realize with the stage of infeed other material c).This can be for example by expecting stream b _lwith a _hmix, and the stage of introducing subsequently c) carries out.

This rectifying tower is preferably to separate and comprises hydrogenchloride photoreactive gas and the structure of the mixture of inert media if possible from gas phase phosgenation step of reaction.

Then will expect stream C _hfeed a rear rectifying e), wherein phosgene and washings are separated from each other.Stage e) should preferably have at least one and have 2-20 theoretical tray, preferably 5-15 theoretical tray, and the particularly preferably stripping stage of 6-10 theoretical tray, makes the high boiler material stream e obtaining in bottom _hsubstantially formed by pure washings and lower boiling material is flowed to e _lin not rectifying of top e) of rectifying and through rectifying e) the isolating active internals at top take out.In this case, material stream e _hsubstantially be made up of washings photoreactive gas and can preferably further do not purify and be recycled to phosgenation, this is because then washings serves as inert media in gas phase phosgenation.

In particularly preferred embodiments, the stage e) has containing 0.5-10 theoretical tray, preferably the enrichment section of 1-5 theoretical tray and contain 2-20 theoretical tray, preferably 5-15 theoretical tray, the particularly preferably stripping stage of 6-10 theoretical tray, and at top at 5-80 DEG C, preferably 10-60 DEG C, particularly preferably 20-40 DEG C, in bottom at 100-200 DEG C, preferably 130-180 DEG C, the particularly preferably temperature of 150-175 DEG C, with 1-5 bar absolute pressure, preferably under 2-3.5 bar absolute pressure, operate.

Stage rectifying e) is for example with 0.1-10, preferably 0.2-5, the particularly preferably reflux ratio of 0.5-2 operation.

Here the vapor stream e obtaining _lsubstantially be made up of pure phosgene, it can be not then preferably further be purified and for phosgenation.High boiler material stream e _hsubstantially be made up of pure washings, it then can be not preferably further be purified and for washing b) and/or quenching.

In second embodiment, carry out the institute of first embodiment in steps, difference is the stage of distilling c) and e) combination in partition tower.The preferred disposition of this partition tower makes inflow side only have stripping stage, and outflow side only has enrichment section.Therefore partition tower makes the gas space of inflow side and outflow side be separated from each other.

Then the gas space of inflow side preferably d) is connected with partial condensation again.In this embodiment, will expect stream c _lfrom the gas space of inflow side, take out the material stream e substantially being formed by phosgene _lfrom the gas space of outflow side, take out the material stream e substantially being formed by washings _htake out combination bottom by outflow and inflow side.

Can select in embodiment at the 3rd, again carry out all features of first embodiment, and the distillation stage c) and e) combination in partition tower equally.But in this case, the preferred disposition of this partition tower makes inflow side and outflow side have separately stripping stage and enrichment section.Therefore low boilers space and high boiling product space interconnect via isolating active internals.Partition tower is separated from each other inflow side and outflow side.

In conjunction with the gas space preferably again d) be connected with partial condensation.In this embodiment, will expect stream c _lfrom the gas space of combination, take out the material stream e substantially being formed by phosgene _ltake out now the material stream e substantially being formed by washings from outflow side as mid-boiling point thing _htake out combination bottom by outflow and inflow side.

According to the present invention, preferably those combination of process steps comprise phosgene to separate, from the solvent of quenching or from the mixture of step washings, hydrogenchloride and chlorine b), wherein washings its be recycled to washing b) and/or quenching in the past through at least one theoretical tray by rectification and purification at least one times.

If treat that the fresh phosgene of the whole technique of infeed separating in the methods of the invention has high chlorine content and/or bromine content, more than above-mentioned limit, according to the present invention, also preferred those combination of process steps, wherein phosgene passed through rectification and purification at least one times through at least one theoretical tray before feeding phosgenation.

Low chlorine of the present invention and/or bromine content can be preferably as follows realization:

1) the fresh phosgene of infeed method has required low chlorine and/or bromine content.

This is particularly preferred for realizing the low bromine content of the present invention.

Low chlorine and bromine content can be by for example feeding the fresh phosgene of the inventive method by activated carbon treatment or realizing by the specific procedure of being synthesized phosgene by chlorine and carbon monoxide.

Phosgene is usually by making carbon monoxide and mol-chloric (Cl ₂) through applicable carrier, preferably gac contacts and prepares.Due to the strong heat release that is formed as of phosgene, this preferably carries out in shell and tube-type reactor, wherein carrier bed is heated to 400 DEG C at the most by thermopositive reaction, but temperature is down to 40-150 DEG C during by pipe.The reaction heat discharging is removed as water by applicable heat-transfer medium.Pressure is generally barometric point or slightly higher than barometric point.

If the preparation of phosgene is used excessive carbon monoxide and the sufficiently long residence time of stoichiometry to carry out, conventionally realize the complete reaction of chlorine.The phosgene obtaining so still comprises a small amount of carbon monoxide.But in the time that phosgene is used for phosgenation, this does not have any disadvantageous effect, this is because the carbon monoxide comprising is used as rare gas element in gas phase phosgenation.

2) if fresh phosgene has relatively high chlorine content, for example, more than 2 ppm by weight, preferably more than 10 ppm by weight, particularly preferably more than 20 ppm by weight, very particularly preferably more than 50 ppm by weight, particularly more than 100 ppm by weight, according to the present invention, fresh phosgene can not directly be introduced and the reacting of amine, but at least partly, preferably all introduce in the separating of the mixture that comprises phosgene and hydrogenchloride being obtained by phosgenation, wherein the resistates of chlorine and/or bromine is isolated together with hydrogenchloride from phosgene.This represents the preferred embodiments of the invention.

That form owing to dissociating by phosgene or can before phosgenation, isolate like this from the chlorine in phosgene preparation, this is favourable.

Hydrogenchloride/phosgene after separating can be at the adsorption unit by separating in the hydrogenchloride material stream of discharging, and preferably activated charcoal filter makes to remove the hydrogenchloride from obtaining trace washing medium.

The vulcabond height of preparing by process for gas phase phosgenation is suitable for preparing polyisocyanates for prepare the polymkeric substance that comprises urethanum, isocyanuric acid ester, acid amides and/or urea groups by polyisocyanate polyaddition method.They are also for the preparation of the polyisocyanate mixtures with urethanum, biuret and/or isocyanurate group modification.This polyisocyanate mixtures that comprises aliphatic series or alicyclic diisocyanate is used in particular for preparing light stable polyurethane paint, varnish and coating and for thermoplastic polyurethane.

Claims (16)

1. prepare a method for vulcabond, wherein make corresponding diamines react at least one reaction zone with stoichiometry excess phosgene,

Wherein to make at least reactive component diamines, vulcabond photoreactive gas be gaseous state under these conditions in the selection of reaction conditions, and

The air-flow that at least one is comprised to diamines and the air-flow that at least one comprises phosgene feed in reaction zone,

During the material that wherein comprised phosgene before mixing with the material stream that comprises amine flows, the massfraction of bromine is for being less than 50 ppm by weight, and temperature in reaction compartment is 260-600 DEG C.

2. according to the process of claim 1 wherein, at least one inert media is added in the air-flow that comprises diamines and/or comprise phosgene inert media is compared for >0.0001 is to≤30 with amine or with the gas volume of phosgene.

3. according to the process of claim 1 wherein that the interior phosgene of reaction compartment clings to the absolute pressure of <20 bar and carries out with reacting at >0.1 of diamines.

4. according to the method for claim 2, wherein in reaction compartment, phosgene clings to the absolute pressure of <20 bar and carries out with reacting at >0.1 of diamines.

5. according to the method for any one in claim 1-4, wherein in reaction compartment, phosgene carries out with reacting at the temperature of 300 to 550 DEG C of diamines.

6. according to the method for any one in claim 1-4, wherein the average contact time of reaction mixture be >=0.001 second to <5 second.

7. according to the method for claim 5, wherein the average contact time of reaction mixture be >=0.001 second to <5 second.

8. according to the method for any one in claim 1-4, wherein phosgene and amino mol ratio are 1.1:1-20:1.

9. according to the method for any one in claim 1-4, wherein mobile in reaction compartment has the Bodenstein value that is greater than 10.

10. according to the method for any one in claim 1-4, in the material stream that wherein comprises phosgene after any and fresh phosgene mix and before mixing with the material stream that comprises amine, the massfraction of hydrogenchloride is for being less than 15 % by weight.

11. according to the method for claim 2, and wherein said inert media is chlorobenzene.

12. according to the method for any one in claim 1-4, wherein said isocyanic ester is selected from 1,6-bis-isocyanato-hexanes, 1-isocyanato--3,3,5-trimethylammonium-5-(isocyanato-methyl) hexanaphthene, 4,4 '-bis-(isocyanato-cyclohexyl) methane and toluene 2,4-/2,6-diisocyanate isomer mixture.

13. according to the method for any one in claim 1-4, wherein make mol-chloric (Cl2) content be more than 2 ppm by weight fresh phosgene at least partly the isolating active internals by rectifying tower to isolate chlorine from phosgene before phosgene reacts with amine.

14. according to the method for claim 13, and wherein said rectifying tower is to separate to comprise hydrogenchloride photoreactive gas and the structure of the mixture of inert media if possible.

15. molecular bromine (Br2) content is the purposes of phosgene in the method for preparing vulcabond that is less than 50 ppm by weight, wherein said method comprises makes corresponding diamines react at least one reaction zone with stoichiometry excess phosgene, wherein to make at least reactive component diamines, vulcabond photoreactive gas be gaseous state under these conditions in the selection of reaction conditions, and

The air-flow that at least one is comprised to diamines and the air-flow that at least one comprises phosgene feed in reaction zone,

And the temperature in reaction compartment is 260-600 DEG C.

16. according to the purposes of claim 15, and wherein the temperature in reaction compartment is 300-550 DEG C.

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